v2.2.4 - Quiet FFmpeg; add "invert" option to Classic Vis; fix CLI parsing for Image component (#96)

* change noisiness of terminal output
ffmpeg no longer prints everything into the terminal unless we're in `--verbose` mode. percentage progress text stays on one line while not in verbose mode.

* Added hint to run `avp --verbose` if `avp --log` is run with no avp_debug.log file present

* Classic Visualizer: add invert option

* Image component: fix path commandline option

* Image component: restrict file formats in CLI to match GUI

* Color component: add tooltip to color2 picker (second color of gradients)

* change tests to work with pytest-xdist
avp core stores its config (location of `settings.ini`) in temp directories if using multiple workers to run tests, so they don't interfere with each other. when using a single worker, the `tests/data/config` directory is still used

* check alt comp names when parsing cmdline

* rename `original.py` to `classic.py`

* move `component.py` into subpackage

* rename comp_original to comp_classic

* show traceback if renderFrame() raises exception

* do not try to insert non-existent components from project files

* add "composite" property for components
if a component returns "composite" then it will receive a frame to draw on during calls to previewRender and frameRender

* more tests of projects, actions, waveform, spectrum, image, color, classic

* do not change presetDir to "projects" within PresetManager

27 files changed, 685 insertions, 578 deletions

diff --git a/src/avp/__init__.py b/src/avp/__init__.py
index 8783660..184afda 100644
--- a/src/avp/__init__.py
+++ b/src/avp/__init__.py
@@ -3,7 +3,7 @@ import os
 import logging
 
 
-__version__ = "2.2.3"
+__version__ = "2.2.4"
 
 
 class Logger(logging.getLoggerClass()):
diff --git a/src/avp/cli.py b/src/avp/cli.py
index 0176f76..7d58fe1 100644
--- a/src/avp/cli.py
+++ b/src/avp/cli.py
@@ -40,10 +40,8 @@ def main() -> int:
     screen = app.primaryScreen()
     if screen is None:
         dpi = None
-        log.error("Could not detect DPI")
     else:
         dpi = screen.physicalDotsPerInchX()
-        log.info("Detected screen DPI: %s", dpi)
 
     # Launch program
     if mode == "commandline":
@@ -53,6 +51,8 @@ def main() -> int:
         mode = main.parseArgs()
         log.debug("Finished creating command object")
 
+    log.info(f"QApplication Platform: {QApplication.platformName()}")
+    log.info(f"Detected screen DPI: {dpi}")
     # Both branches here may occur in one execution:
     # Commandline parsing could change mode back to GUI
     if mode == "GUI":
diff --git a/src/avp/command.py b/src/avp/command.py
index 870391b..b6700a5 100644
--- a/src/avp/command.py
+++ b/src/avp/command.py
@@ -14,7 +14,8 @@ import signal
 import shutil
 import logging
 
-from . import core, __version__
+from . import __version__
+from .core import Core
 
 
 log = logging.getLogger("AVP.Commandline")
@@ -29,11 +30,11 @@ class Command(QtCore.QObject):
 
     def __init__(self):
         super().__init__()
-        self.core = core.Core()
-        core.Core.mode = "commandline"
+        self.core = Core()
+        Core.mode = "commandline"
         self.dataDir = self.core.dataDir
         self.canceled = False
-        self.settings = core.Core.settings
+        self.settings = Core.settings
 
         # ctrl-c stops the export thread
         signal.signal(signal.SIGINT, self.stopVideo)
@@ -71,9 +72,10 @@ class Command(QtCore.QObject):
             help="copy and shorten recent log files into ~/avp_log.txt",
         )
         debugCommands.add_argument(
-            "--verbose", "-v",
+            "--verbose",
+            "-v",
             action="store_true",
-            help="create bigger logfiles while program is running",
+            help="send log messages and ffmpeg output to stdout, and create more verbose log files (good to use before --log)",
         )
 
         # project/GUI options
@@ -101,8 +103,8 @@ class Command(QtCore.QObject):
         args = parser.parse_args()
 
         if args.verbose:
-            core.STDOUT_LOGLVL = logging.DEBUG
-            core.Core.makeLogger(deleteOldLogs=False, fileLogLvl=logging.DEBUG)
+            Core.stdoutLogLvl = logging.DEBUG
+            Core.makeLogger(deleteOldLogs=False, fileLogLvl=logging.DEBUG)
 
         if args.log:
             self.createLogFile()
@@ -168,7 +170,7 @@ class Command(QtCore.QObject):
             return "commandline"
 
         elif args.no_preview:
-            core.Core.previewEnabled = False
+            Core.previewEnabled = False
 
         elif (
             args.projpath is None
@@ -203,20 +205,18 @@ class Command(QtCore.QObject):
 
     @QtCore.pyqtSlot(str)
     def progressBarSetText(self, value):
-        if "Export " in value:
-            # Don't duplicate completion/failure messages
+        if "Export " in value or time.time() - self.lastProgressUpdate < 0.1:
+            # Don't duplicate completion/failure messages or send too many messages
             return
-        if (
-            not value.startswith("Exporting")
-            and time.time() - self.lastProgressUpdate >= 0.05
-        ):
+
+        if not value.endswith("%"):
             # Show most messages very often
             print(value)
-        elif time.time() - self.lastProgressUpdate >= 2.0:
-            # Give user time to read ffmpeg's output during the export
-            print("##### %s" % value)
-        else:
-            return
+        elif log.getEffectiveLevel() > logging.INFO:
+            # if ffmpeg isn't printing export progress for us,
+            # then overwrite previous message with the next one
+            # if this text is our main export progress
+            print(f"{value}\r", end="")
         self.lastProgressUpdate = time.time()
 
     @QtCore.pyqtSlot()
@@ -224,6 +224,7 @@ class Command(QtCore.QObject):
         self.quit(0)
 
     def quit(self, code):
+        print()
         quit(code)
 
     def showMessage(self, **kwargs):
@@ -242,12 +243,14 @@ class Command(QtCore.QObject):
 
     def parseCompName(self, name):
         """Deduces a proper component name out of a commandline arg"""
-
         if name.title() in self.core.compNames:
             return name.title()
         for compName in self.core.compNames:
             if name.capitalize() in compName:
                 return compName
+        for altName, moduleIndex in self.core.altCompNames:
+            if name.title() in altName:
+                return self.core.compNames[moduleIndex]
 
         compFileNames = [
             os.path.splitext(os.path.basename(mod.__file__))[0]
@@ -281,16 +284,17 @@ class Command(QtCore.QObject):
             print("Log file could not be created (too many exist).")
             return
         try:
-            shutil.copy(os.path.join(core.Core.logDir, "avp_debug.log"), filename)
+            shutil.copy(os.path.join(Core.logDir, "avp_debug.log"), filename)
             with open(filename, "a") as f:
                 f.write(f"{'='*60} debug log ends {'='*60}\n")
         except FileNotFoundError:
+            print("No debug log was found. Run `avp --verbose` before `avp --log`.")
             with open(filename, "w") as f:
                 f.write(f"{'='*60} no debug log {'='*60}\n")
 
         def concatenateLogs(logPattern):
             nonlocal filename
-            renderLogs = glob.glob(os.path.join(core.Core.logDir, logPattern))
+            renderLogs = glob.glob(os.path.join(Core.logDir, logPattern))
             with open(filename, "a") as fw:
                 for renderLog in renderLogs:
                     with open(renderLog, "r") as fr:
diff --git a/src/avp/components/original.py b/src/avp/components/classic.py
index 0da78dc..72089af 100644
--- a/src/avp/components/original.py
+++ b/src/avp/components/classic.py
@@ -1,21 +1,23 @@
 import numpy
 from PIL import Image, ImageDraw
-from copy import copy
 
-from ..component import Component
-from ..toolkit.frame import BlankFrame
+from ..libcomponent import BaseComponent
+from ..toolkit.frame import BlankFrame, FloodFrame
 from ..toolkit.visualizer import createSpectrumArray
 
 
-class Component(Component):
+class Component(BaseComponent):
     name = "Classic Visualizer"
-    version = "1.1.0"
+    version = "1.2.0"
 
     def names(*args):
-        return ["Original Audio Visualization"]
+        return ["Original"]
 
     def properties(self):
-        return ["pcm"]
+        props = ["pcm"]
+        if self.invert:
+            props.append("composite")
+        return props
 
     def widget(self, *args):
         self.scale = 20
@@ -37,6 +39,7 @@ class Component(Component):
                 "y": self.page.spinBox_y,
                 "smooth": self.page.spinBox_sensitivity,
                 "bars": self.page.spinBox_bars,
+                "invert": self.page.checkBox_invert,
             },
             colorWidgets={
                 "visColor": self.page.pushButton_visColor,
@@ -46,14 +49,19 @@ class Component(Component):
             ],
         )
 
-    def previewRender(self):
+    def previewRender(self, frame=None):
         spectrum = numpy.fromfunction(
             lambda x: float(self.scale) / 2500 * (x - 128) ** 2,
             (255,),
             dtype="int16",
         )
         return self.drawBars(
-            self.width, self.height, spectrum, self.visColor, self.layout
+            self.width,
+            self.height,
+            spectrum,
+            self.visColor,
+            self.layout,
+            frame,
         )
 
     def preFrameRender(self, **kwargs):
@@ -71,7 +79,7 @@ class Component(Component):
             self.progressBarSetText,
         )
 
-    def frameRender(self, frameNo):
+    def frameRender(self, frameNo, frame=None):
         arrayNo = frameNo * self.sampleSize
         return self.drawBars(
             self.width,
@@ -79,9 +87,10 @@ class Component(Component):
             self.spectrumArray[arrayNo],
             self.visColor,
             self.layout,
+            frame,
         )
 
-    def drawBars(self, width, height, spectrum, color, layout):
+    def drawBars(self, width, height, spectrum, color, layout, frame):
         bigYCoord = height - height / 8
         smallYCoord = height / 1200
         bigXCoord = width / (self.bars + 1)
@@ -94,32 +103,44 @@ class Component(Component):
         color2 = (r, g, b, 125)
 
         for i in range(self.bars):
-            x0 = middleXCoord + i * bigXCoord
-            y0 = bigYCoord + smallXCoord
-            y1 = bigYCoord + smallXCoord - spectrum[i * 4] * smallYCoord - middleXCoord
-            x1 = middleXCoord + i * bigXCoord + bigXCoord
-            draw.rectangle(
-                (
+            # draw outline behind rectangles if not inverted
+            if frame is None:
+                x0 = middleXCoord + i * bigXCoord
+                y0 = bigYCoord + smallXCoord
+                x1 = middleXCoord + i * bigXCoord + bigXCoord
+                y1 = (
+                    bigYCoord
+                    + smallXCoord
+                    - spectrum[i * 4] * smallYCoord
+                    - middleXCoord
+                )
+                selection = (
                     x0,
                     y0 if y0 < y1 else y1,
                     x1 if x1 > x0 else x0,
                     y1 if y0 < y1 else y0,
-                ),
-                fill=color2,
-            )
+                )
+                draw.rectangle(
+                    selection,
+                    fill=color2,
+                )
 
             x0 = middleXCoord + smallXCoord + i * bigXCoord
             y0 = bigYCoord
             x1 = middleXCoord + smallXCoord + i * bigXCoord + middleXCoord
             y1 = bigYCoord - spectrum[i * 4] * smallYCoord
+            selection = (
+                x0,
+                y0 if y0 < y1 else y1,
+                x1 if x1 > x0 else x0,
+                y1 if y0 < y1 else y0,
+            )
+            # fill rectangle if not inverted
             draw.rectangle(
-                (
-                    x0,
-                    y0 if y0 < y1 else y1,
-                    x1 if x1 > x0 else x0,
-                    y1 if y0 < y1 else y0,
-                ),
-                fill=color,
+                selection,
+                fill=color if frame is None else (0, 0, 0, 0),
+                outline=color,
+                width=int(x1 - x0),
             )
 
         imBottom = imTop.transpose(Image.Transpose.FLIP_TOP_BOTTOM)
@@ -146,7 +167,11 @@ class Component(Component):
             y = self.y - int(height / 100 * 10)
             im.paste(imBottom, (0, y), mask=imBottom)
 
-        return im
+        if frame is None:
+            return im
+        f = FloodFrame(width, height, color)
+        f.paste(frame, (0, 0), mask=im)
+        return f
 
     def command(self, arg):
         if "=" in arg:
diff --git a/src/avp/components/original.ui b/src/avp/components/classic.ui
index 8dbdaa2..1ae7faa 100644
--- a/src/avp/components/original.ui
+++ b/src/avp/components/classic.ui
@@ -86,7 +86,7 @@
      <item>
       <widget class="QLineEdit" name="lineEdit_visColor">
        <property name="text">
-        <string></string>
+        <string/>
        </property>
       </widget>
      </item>
@@ -233,6 +233,13 @@
       </widget>
      </item>
      <item>
+      <widget class="QCheckBox" name="checkBox_invert">
+       <property name="text">
+        <string>Invert</string>
+       </property>
+      </widget>
+     </item>
+     <item>
       <spacer name="horizontalSpacer">
        <property name="orientation">
         <enum>Qt::Orientation::Horizontal</enum>
diff --git a/src/avp/components/color.py b/src/avp/components/color.py
index cb0960a..826f37f 100644
--- a/src/avp/components/color.py
+++ b/src/avp/components/color.py
@@ -1,14 +1,14 @@
 from PyQt6 import QtGui
 import logging
 
-from ..component import Component
+from ..libcomponent import BaseComponent
 from ..toolkit.frame import BlankFrame, FloodFrame, FramePainter
 
 
 log = logging.getLogger("AVP.Components.Color")
 
 
-class Component(Component):
+class Component(BaseComponent):
     name = "Color"
     version = "1.0.0"
 
diff --git a/src/avp/components/color.ui b/src/avp/components/color.ui
index c36bdd8..788adb9 100644
--- a/src/avp/components/color.ui
+++ b/src/avp/components/color.ui
@@ -124,6 +124,9 @@
            <height>32</height>
           </size>
          </property>
+         <property name="toolTip">
+          <string>End color of gradient. Disabled if fill is solid.</string>
+         </property>
          <property name="text">
           <string/>
          </property>
diff --git a/src/avp/components/image.py b/src/avp/components/image.py
index e012cec..a082092 100644
--- a/src/avp/components/image.py
+++ b/src/avp/components/image.py
@@ -1,14 +1,13 @@
 from PIL import Image, ImageOps, ImageEnhance
 from PyQt6 import QtWidgets
 import os
-from copy import copy
 
-from ..component import Component
+from ..libcomponent import BaseComponent
 from ..toolkit.frame import BlankFrame, addShadow
 from ..toolkit.visualizer import createSpectrumArray
 
 
-class Component(Component):
+class Component(BaseComponent):
     name = "Image"
     version = "2.1.0"
 
@@ -177,17 +176,22 @@ class Component(Component):
             self.mergeUndo = True
 
     def command(self, arg):
+        def fail():
+            print("Not a supported image format")
+            quit(1)
+
         if "=" in arg:
             key, arg = arg.split("=", 1)
             if key == "path" and os.path.exists(arg):
+                if f"*{os.path.splitext(arg)[1]}" not in self.core.imageFormats:
+                    fail()
                 try:
                     Image.open(arg)
                     self.page.lineEdit_image.setText(arg)
-                    self.page.checkBox_stretch.setChecked(True)
+                    self.page.comboBox_resizeMode.setCurrentIndex(2)
                     return
                 except OSError as e:
-                    print("Not a supported image format")
-                    quit(1)
+                    fail()
         super().command(arg)
 
     def commandHelp(self):
diff --git a/src/avp/components/life.py b/src/avp/components/life.py
index a062617..374b299 100644
--- a/src/avp/components/life.py
+++ b/src/avp/components/life.py
@@ -1,13 +1,12 @@
 from PyQt6 import QtCore, QtWidgets
 from PyQt6.QtGui import QUndoCommand
-from PIL import Image, ImageDraw, ImageEnhance, ImageChops, ImageFilter, ImageOps
+from PIL import Image, ImageDraw
 import os
-from copy import copy
 import math
 import logging
 
 
-from ..component import Component
+from ..libcomponent import BaseComponent
 from ..toolkit.frame import BlankFrame, scale, addShadow
 from ..toolkit.visualizer import createSpectrumArray
 
@@ -15,7 +14,7 @@ from ..toolkit.visualizer import createSpectrumArray
 log = logging.getLogger("AVP.Component.Life")
 
 
-class Component(Component):
+class Component(BaseComponent):
     name = "Conway's Game of Life"
     version = "2.0.1"
 
diff --git a/src/avp/components/sound.py b/src/avp/components/sound.py
index 2df8e38..c212870 100644
--- a/src/avp/components/sound.py
+++ b/src/avp/components/sound.py
@@ -1,11 +1,11 @@
-from PyQt6 import QtGui, QtCore, QtWidgets
+from PyQt6 import QtWidgets
 import os
 
-from ..component import Component
+from ..libcomponent import BaseComponent
 from ..toolkit.frame import BlankFrame
 
 
-class Component(Component):
+class Component(BaseComponent):
     name = "Sound"
     version = "1.0.0"
 
diff --git a/src/avp/components/spectrum.py b/src/avp/components/spectrum.py
index 062ebc7..0446865 100644
--- a/src/avp/components/spectrum.py
+++ b/src/avp/components/spectrum.py
@@ -1,14 +1,11 @@
 from PIL import Image
-from PyQt6 import QtGui, QtCore, QtWidgets
 import os
-import math
 import subprocess
-import time
 import logging
 
-from ..component import Component
+from ..libcomponent import BaseComponent
 from ..toolkit.frame import BlankFrame, scale
-from ..toolkit import checkOutput, connectWidget
+from ..toolkit import connectWidget
 from ..toolkit.ffmpeg import (
     openPipe,
     closePipe,
@@ -21,7 +18,7 @@ from ..toolkit.ffmpeg import (
 log = logging.getLogger("AVP.Components.Spectrum")
 
 
-class Component(Component):
+class Component(BaseComponent):
     name = "Spectrum"
     version = "1.0.1"
 
diff --git a/src/avp/components/text.py b/src/avp/components/text.py
index bee117e..d248772 100644
--- a/src/avp/components/text.py
+++ b/src/avp/components/text.py
@@ -1,16 +1,14 @@
-from PIL import ImageEnhance, ImageFilter, ImageChops
-from PyQt6.QtGui import QColor, QFont
-from PyQt6 import QtGui, QtCore, QtWidgets
-import os
+from PyQt6.QtGui import QFont
+from PyQt6 import QtGui, QtCore
 import logging
 
-from ..component import Component
+from ..libcomponent import BaseComponent
 from ..toolkit.frame import FramePainter, addShadow
 
 log = logging.getLogger("AVP.Components.Text")
 
 
-class Component(Component):
+class Component(BaseComponent):
     name = "Title Text"
     version = "1.0.1"
 
diff --git a/src/avp/components/video.py b/src/avp/components/video.py
index 65a05af..1e9b788 100644
--- a/src/avp/components/video.py
+++ b/src/avp/components/video.py
@@ -1,20 +1,18 @@
 from PIL import Image
-from PyQt6 import QtGui, QtCore, QtWidgets
+from PyQt6 import QtWidgets
 import os
-import math
 import subprocess
 import logging
 
-from ..component import Component
+from ..libcomponent import BaseComponent
 from ..toolkit.frame import BlankFrame, scale
 from ..toolkit.ffmpeg import openPipe, closePipe, testAudioStream, FfmpegVideo
-from ..toolkit import checkOutput
 
 
 log = logging.getLogger("AVP.Components.Video")
 
 
-class Component(Component):
+class Component(BaseComponent):
     name = "Video"
     version = "1.0.0"
 
diff --git a/src/avp/components/waveform.py b/src/avp/components/waveform.py
index e10dec2..bfebc30 100644
--- a/src/avp/components/waveform.py
+++ b/src/avp/components/waveform.py
@@ -3,12 +3,10 @@ from PyQt6.QtGui import QColor
 import os
 import subprocess
 import logging
-from copy import copy
 
-from ..component import Component
-from ..toolkit.visualizer import transformData, createSpectrumArray
+from ..libcomponent import BaseComponent
+from ..toolkit.visualizer import createSpectrumArray
 from ..toolkit.frame import BlankFrame, scale
-from ..toolkit import checkOutput
 from ..toolkit.ffmpeg import (
     openPipe,
     closePipe,
@@ -21,7 +19,7 @@ from ..toolkit.ffmpeg import (
 log = logging.getLogger("AVP.Components.Waveform")
 
 
-class Component(Component):
+class Component(BaseComponent):
     name = "Waveform"
     version = "2.0.0"
 
diff --git a/src/avp/core.py b/src/avp/core.py
index 347a5dd..c8e070b 100644
--- a/src/avp/core.py
+++ b/src/avp/core.py
@@ -14,7 +14,6 @@ from . import toolkit
 
 appName = "Audio Visualizer Python"
 log = logging.getLogger("AVP.Core")
-STDOUT_LOGLVL = logging.WARNING
 
 
 class Core:
@@ -26,6 +25,8 @@ class Core:
     This class also stores constants as class variables.
     """
 
+    stdoutLogLvl = logging.WARNING
+
     def __init__(self):
         self.importComponents()
         self.selectedComponents = []
@@ -77,7 +78,10 @@ class Core:
             compPos = len(self.selectedComponents)
         if len(self.selectedComponents) > 50:
             return -1
-        if type(component) is int:
+        if component is None:
+            log.warning("Tried to insert non-existent component")
+            return -1
+        elif type(component) is int:
             # create component using module index in self.modules
             moduleIndex = int(component)
             log.debug("Creating new component from module #%s", str(moduleIndex))
@@ -197,7 +201,7 @@ class Core:
                         )
                         continue
                     if i == -1:
-                        loader.showMessage(msg="Too many components!")
+                        loader.showMessage(msg="Invalid components!")
                         break
 
                     try:
@@ -554,7 +558,7 @@ class Core:
     def makeLogger(deleteOldLogs=False, fileLogLvl=None):
         # send critical log messages to stdout
         logStream = logging.StreamHandler()
-        logStream.setLevel(STDOUT_LOGLVL)
+        logStream.setLevel(Core.stdoutLogLvl)
         streamFormatter = logging.Formatter("<%(name)s> %(levelname)s: %(message)s")
         logStream.setFormatter(streamFormatter)
         log = logging.getLogger("AVP")
diff --git a/src/avp/gui/actions.py b/src/avp/gui/actions.py
index 654b2a0..6a01bdd 100644
--- a/src/avp/gui/actions.py
+++ b/src/avp/gui/actions.py
@@ -1,5 +1,5 @@
 """
-QCommand classes for every undoable user action performed in the MainWindow
+QUndoCommand classes for every undoable user action performed in the MainWindow
 """
 
 from PyQt6.QtGui import QUndoCommand
@@ -13,9 +13,9 @@ from ..core import Core
 log = logging.getLogger("AVP.Gui.Actions")
 
 
-# =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+# =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
 # COMPONENT ACTIONS
-# =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+# =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
 
 
 class AddComponent(QUndoCommand):
@@ -107,9 +107,9 @@ class MoveComponent(QUndoCommand):
         self.do(self.newRow, self.row)
 
 
-# =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+# =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
 # PRESET ACTIONS
-# =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+# =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
 
 
 class ClearPreset(QUndoCommand):
diff --git a/src/avp/gui/mainwindow.py b/src/avp/gui/mainwindow.py
index 3221783..fac1e41 100644
--- a/src/avp/gui/mainwindow.py
+++ b/src/avp/gui/mainwindow.py
@@ -25,7 +25,7 @@ from . import preview_thread
 from .preview_win import PreviewWindow
 from .presetmanager import PresetManager
 from .actions import *
-from ..toolkit.ffmpeg import createFfmpegCommand
+from ..toolkit.ffmpeg import createFfmpegCommand, checkFfmpegVersion
 from ..toolkit import (
     disableWhenEncoding,
     disableWhenOpeningProject,
@@ -330,26 +330,13 @@ class MainWindow(QtWidgets.QMainWindow):
             )
         else:
             if not self.settings.value("ffmpegMsgShown"):
-                try:
-                    with open(os.devnull, "w") as f:
-                        ffmpegVers = checkOutput(
-                            [self.core.FFMPEG_BIN, "-version"], stderr=f
-                        )
-                    ffmpegVers = str(ffmpegVers).split()[2].split(".", 1)[0]
-                    if ffmpegVers.startswith("n"):
-                        ffmpegVers = ffmpegVers[1:]
-                    goodVersion = int(ffmpegVers) > 3
-                except Exception:
-                    goodVersion = False
-            else:
-                goodVersion = True
-
-            if not goodVersion:
-                self.showMessage(
-                    msg="You're using an old version of Ffmpeg. "
-                    "Some features may not work as expected."
-                )
-            self.settings.setValue("ffmpegMsgShown", True)
+                ffmpegGoodVersion, ffmpegVersionNum = checkFfmpegVersion()
+                if not ffmpegGoodVersion:
+                    self.showMessage(
+                        msg="The version of FFmpeg ({ffmpegVersionNum}) is "
+                        "not recognized. Some features may not work as expected."
+                    )
+                self.settings.setValue("ffmpegMsgShown", True)
 
         # Hotkeys for projects
 
@@ -734,6 +721,23 @@ class MainWindow(QtWidgets.QMainWindow):
             self.progressLabel.setText(value)
         else:
             self.progressBar_createVideo.setFormat(value)
+        if log.getEffectiveLevel() > logging.INFO:
+            # if ffmpeg is quiet, print progress ourselves
+            if any(
+                [
+                    value.startswith("Export C"),
+                    value.startswith("Analyzing"),
+                    value.startswith("Loading"),
+                ]
+            ):
+                # Don't duplicate completion/failure messages or send too many messages
+                return
+            elif not value.startswith("Exporting"):
+                print(value)
+            else:
+                # overwrite previous message with next one
+                # if the text is our main export progress
+                print(f"\r{value}", end="")
 
     def updateResolution(self):
         resIndex = int(self.comboBox_resolution.currentIndex())
diff --git a/src/avp/gui/presetmanager.py b/src/avp/gui/presetmanager.py
index ca0029d..bdcff91 100644
--- a/src/avp/gui/presetmanager.py
+++ b/src/avp/gui/presetmanager.py
@@ -25,9 +25,7 @@ class PresetManager(QtWidgets.QDialog):
         self.settings = parent.settings
         self.presetDir = parent.presetDir
         if not self.settings.value("presetDir"):
-            self.settings.setValue(
-                "presetDir", os.path.join(parent.dataDir, "projects")
-            )
+            self.settings.setValue("presetDir", os.path.join(parent.dataDir, "presets"))
 
         self.findPresets()
 
diff --git a/src/avp/gui/preview_thread.py b/src/avp/gui/preview_thread.py
index a59652a..8507f45 100644
--- a/src/avp/gui/preview_thread.py
+++ b/src/avp/gui/preview_thread.py
@@ -61,7 +61,10 @@ class Worker(QtCore.QObject):
             for component in reversed(components):
                 try:
                     component.lockSize(width, height)
-                    newFrame = component.previewRender()
+                    if "composite" in component.properties():
+                        newFrame = component.previewRender(frame)
+                    else:
+                        newFrame = component.previewRender()
                     component.unlockSize()
                     frame = Image.alpha_composite(frame, newFrame)
 
@@ -72,11 +75,12 @@ class Worker(QtCore.QObject):
                         % (
                             str(component),
                             str(e).capitalize(),
-                            "is None" if newFrame is None else "size was %s*%s; should be %s*%s" % (
-                                newFrame.width,
-                                newFrame.height,
-                                width,
-                                height),
+                            (
+                                "is None"
+                                if newFrame is None
+                                else "size was %s*%s; should be %s*%s"
+                                % (newFrame.width, newFrame.height, width, height)
+                            ),
                         )
                     )
                     log.critical(errMsg)
diff --git a/src/avp/libcomponent/__init__.py b/src/avp/libcomponent/__init__.py
new file mode 100644
index 0000000..5b04b45
--- /dev/null
+++ b/src/avp/libcomponent/__init__.py
@@ -0,0 +1,4 @@
+from .component import Component as BaseComponent
+from .exceptions import ComponentError
+
+__all__ = [BaseComponent, ComponentError]
diff --git a/src/avp/libcomponent/actions.py b/src/avp/libcomponent/actions.py
new file mode 100644
index 0000000..f534685
--- /dev/null
+++ b/src/avp/libcomponent/actions.py
@@ -0,0 +1,104 @@
+"""
+QUndoCommand class for generic undoable user actions performed to a BaseComponent
+
+See `../life.py` for an example of a component that uses a custom QUndoCommand
+"""
+
+from PyQt6.QtGui import QUndoCommand
+from copy import copy
+import logging
+
+log = logging.getLogger("AVP.ComponentHandler")
+
+
+class ComponentUpdate(QUndoCommand):
+    """Command object for making a component action undoable"""
+
+    def __init__(self, parent, oldWidgetVals, modifiedVals):
+        super().__init__("change %s component #%s" % (parent.name, parent.compPos))
+        self.undone = False
+        self.res = (int(parent.width), int(parent.height))
+        self.parent = parent
+        self.oldWidgetVals = {
+            attr: (
+                copy(val)
+                if attr not in self.parent._relativeWidgets
+                else self.parent.floatValForAttr(attr, val, axis=self.res)
+            )
+            for attr, val in oldWidgetVals.items()
+            if attr in modifiedVals
+        }
+        self.modifiedVals = {
+            attr: (
+                val
+                if attr not in self.parent._relativeWidgets
+                else self.parent.floatValForAttr(attr, val, axis=self.res)
+            )
+            for attr, val in modifiedVals.items()
+        }
+
+        # Because relative widgets change themselves every update based on
+        # their previous value, we must store ALL their values in case of undo
+        self.relativeWidgetValsAfterUndo = {
+            attr: copy(getattr(self.parent, attr))
+            for attr in self.parent._relativeWidgets
+        }
+
+        # Determine if this update is mergeable
+        self.id_ = -1
+        if self.parent.mergeUndo:
+            if len(self.modifiedVals) == 1:
+                attr, val = self.modifiedVals.popitem()
+                self.id_ = sum([ord(letter) for letter in attr[-14:]])
+                self.modifiedVals[attr] = val
+                return
+            log.warning(
+                "%s component settings changed at once. (%s)",
+                len(self.modifiedVals),
+                repr(self.modifiedVals),
+            )
+
+    def id(self):
+        """If 2 consecutive updates have same id, Qt will call mergeWith()"""
+        return self.id_
+
+    def mergeWith(self, other):
+        self.modifiedVals.update(other.modifiedVals)
+        return True
+
+    def setWidgetValues(self, attrDict):
+        """
+        Mask the component's usual method to handle our
+        relative widgets in case the resolution has changed.
+        """
+        newAttrDict = {
+            attr: (
+                val
+                if attr not in self.parent._relativeWidgets
+                else self.parent.pixelValForAttr(attr, val)
+            )
+            for attr, val in attrDict.items()
+        }
+        self.parent.setWidgetValues(newAttrDict)
+
+    def redo(self):
+        if self.undone:
+            log.info("Redoing component update")
+        self.parent.oldAttrs = self.relativeWidgetValsAfterUndo
+        self.setWidgetValues(self.modifiedVals)
+        self.parent.update(auto=True)
+        self.parent.oldAttrs = None
+        if not self.undone:
+            self.relativeWidgetValsAfterRedo = {
+                attr: copy(getattr(self.parent, attr))
+                for attr in self.parent._relativeWidgets
+            }
+            self.parent._sendUpdateSignal()
+
+    def undo(self):
+        log.info("Undoing component update")
+        self.undone = True
+        self.parent.oldAttrs = self.relativeWidgetValsAfterRedo
+        self.setWidgetValues(self.oldWidgetVals)
+        self.parent.update(auto=True)
+        self.parent.oldAttrs = None
diff --git a/src/avp/component.py b/src/avp/libcomponent/component.py
index 5906ab1..1f81e07 100644
--- a/src/avp/component.py
+++ b/src/avp/libcomponent/component.py
@@ -4,274 +4,26 @@ on making a valid component.
 """
 
 from PyQt6 import uic, QtCore, QtWidgets
-from PyQt6.QtGui import QColor, QUndoCommand
+from PyQt6.QtGui import QColor
 import os
-import sys
 import math
-import time
 import logging
 from copy import copy
 
-from .toolkit.frame import BlankFrame
-from .toolkit import (
+from .metaclass import ComponentMetaclass
+from .actions import ComponentUpdate
+from .exceptions import ComponentError
+from ..toolkit.frame import BlankFrame
+
+from ..toolkit import (
     getWidgetValue,
     setWidgetValue,
-    connectWidget,
     rgbFromString,
     randomColor,
     blockSignals,
 )
 
-
-log = logging.getLogger("AVP.ComponentHandler")
-
-
-class ComponentMetaclass(type(QtCore.QObject)):
-    """
-    Checks the validity of each Component class and mutates some attrs.
-    E.g., takes only major version from version string & decorates methods
-    """
-
-    def initializationWrapper(func):
-        def initializationWrapper(self, *args, **kwargs):
-            try:
-                return func(self, *args, **kwargs)
-            except Exception:
-                try:
-                    raise ComponentError(self, "initialization process")
-                except ComponentError:
-                    return
-
-        return initializationWrapper
-
-    def renderWrapper(func):
-        def renderWrapper(self, *args, **kwargs):
-            try:
-                log.verbose(
-                    "### %s #%s renders a preview frame ###",
-                    self.__class__.name,
-                    str(self.compPos),
-                )
-                return func(self, *args, **kwargs)
-            except Exception as e:
-                try:
-                    if e.__class__.__name__.startswith("Component"):
-                        raise
-                    else:
-                        raise ComponentError(self, "renderer")
-                except ComponentError:
-                    return BlankFrame()
-
-        return renderWrapper
-
-    def commandWrapper(func):
-        """Intercepts the command() method to check for global args"""
-
-        def commandWrapper(self, arg):
-            if arg.startswith("preset="):
-                _, preset = arg.split("=", 1)
-                path = os.path.join(self.core.getPresetDir(self), preset)
-                if not os.path.exists(path):
-                    print('Couldn\'t locate preset "%s"' % preset)
-                    quit(1)
-                else:
-                    print('Opening "%s" preset on layer %s' % (preset, self.compPos))
-                    self.core.openPreset(path, self.compPos, preset)
-                    # Don't call the component's command() method
-                    return
-            else:
-                return func(self, arg)
-
-        return commandWrapper
-
-    def propertiesWrapper(func):
-        """Intercepts the usual properties if the properties are locked."""
-
-        def propertiesWrapper(self):
-            if self._lockedProperties is not None:
-                return self._lockedProperties
-            else:
-                try:
-                    return func(self)
-                except Exception:
-                    try:
-                        raise ComponentError(self, "properties")
-                    except ComponentError:
-                        return []
-
-        return propertiesWrapper
-
-    def errorWrapper(func):
-        """Intercepts the usual error message if it is locked."""
-
-        def errorWrapper(self):
-            if self._lockedError is not None:
-                return self._lockedError
-            else:
-                return func(self)
-
-        return errorWrapper
-
-    def loadPresetWrapper(func):
-        """Wraps loadPreset to handle the self.openingPreset boolean"""
-
-        class openingPreset:
-            def __init__(self, comp):
-                self.comp = comp
-
-            def __enter__(self):
-                self.comp.openingPreset = True
-
-            def __exit__(self, *args):
-                self.comp.openingPreset = False
-
-        def presetWrapper(self, *args):
-            with openingPreset(self):
-                try:
-                    return func(self, *args)
-                except Exception:
-                    try:
-                        raise ComponentError(self, "preset loader")
-                    except ComponentError:
-                        return
-
-        return presetWrapper
-
-    def updateWrapper(func):
-        """
-        Calls _preUpdate before every subclass update().
-        Afterwards, for non-user updates, calls _autoUpdate().
-        For undoable updates triggered by the user, calls _userUpdate()
-        """
-
-        class wrap:
-            def __init__(self, comp, auto):
-                self.comp = comp
-                self.auto = auto
-
-            def __enter__(self):
-                self.comp._preUpdate()
-
-            def __exit__(self, *args):
-                if (
-                    self.auto
-                    or self.comp.openingPreset
-                    or not hasattr(self.comp.parent, "undoStack")
-                ):
-                    log.verbose("Automatic update")
-                    self.comp._autoUpdate()
-                else:
-                    log.verbose("User update")
-                    self.comp._userUpdate()
-
-        def updateWrapper(self, **kwargs):
-            auto = kwargs["auto"] if "auto" in kwargs else False
-            with wrap(self, auto):
-                try:
-                    return func(self)
-                except Exception:
-                    try:
-                        raise ComponentError(self, "update method")
-                    except ComponentError:
-                        return
-
-        return updateWrapper
-
-    def widgetWrapper(func):
-        """Connects all widgets to update method after the subclass's method"""
-
-        class wrap:
-            def __init__(self, comp):
-                self.comp = comp
-
-            def __enter__(self):
-                pass
-
-            def __exit__(self, *args):
-                for widgetList in self.comp._allWidgets.values():
-                    for widget in widgetList:
-                        log.verbose("Connecting %s", str(widget.__class__.__name__))
-                        connectWidget(widget, self.comp.update)
-
-        def widgetWrapper(self, *args, **kwargs):
-            auto = kwargs["auto"] if "auto" in kwargs else False
-            with wrap(self):
-                try:
-                    return func(self, *args, **kwargs)
-                except Exception:
-                    try:
-                        raise ComponentError(self, "widget creation")
-                    except ComponentError:
-                        return
-
-        return widgetWrapper
-
-    def __new__(cls, name, parents, attrs):
-        if "ui" not in attrs:
-            # Use module name as ui filename by default
-            attrs["ui"] = (
-                "%s.ui" % os.path.splitext(attrs["__module__"].split(".")[-1])[0]
-            )
-
-        decorate = (
-            "names",  # Class methods
-            "error",
-            "audio",
-            "properties",  # Properties
-            "preFrameRender",
-            "previewRender",
-            "loadPreset",
-            "command",
-            "update",
-            "widget",
-        )
-
-        # Auto-decorate methods
-        for key in decorate:
-            if key not in attrs:
-                continue
-            if key in ("names"):
-                attrs[key] = classmethod(attrs[key])
-            elif key in ("audio"):
-                attrs[key] = property(attrs[key])
-            elif key == "command":
-                attrs[key] = cls.commandWrapper(attrs[key])
-            elif key == "previewRender":
-                attrs[key] = cls.renderWrapper(attrs[key])
-            elif key == "preFrameRender":
-                attrs[key] = cls.initializationWrapper(attrs[key])
-            elif key == "properties":
-                attrs[key] = cls.propertiesWrapper(attrs[key])
-            elif key == "error":
-                attrs[key] = cls.errorWrapper(attrs[key])
-            elif key == "loadPreset":
-                attrs[key] = cls.loadPresetWrapper(attrs[key])
-            elif key == "update":
-                attrs[key] = cls.updateWrapper(attrs[key])
-            elif key == "widget" and parents[0] != QtCore.QObject:
-                attrs[key] = cls.widgetWrapper(attrs[key])
-
-        # Turn version string into a number
-        try:
-            if "version" not in attrs:
-                log.error(
-                    "No version attribute in %s. Defaulting to 1",
-                    attrs["name"],
-                )
-                attrs["version"] = 1
-            else:
-                attrs["version"] = int(attrs["version"].split(".")[0])
-        except ValueError:
-            log.critical(
-                "%s component has an invalid version string:\n%s",
-                attrs["name"],
-                str(attrs["version"]),
-            )
-        except KeyError:
-            log.critical("%s component has no version string.", attrs["name"])
-        else:
-            return super().__new__(cls, name, parents, attrs)
-        quit(1)
+log = logging.getLogger("AVP.BaseComponent")
 
 
 class Component(QtCore.QObject, metaclass=ComponentMetaclass):
@@ -340,9 +92,9 @@ class Component(QtCore.QObject, metaclass=ComponentMetaclass):
             pprint.pformat(preset),
         )
 
-    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
     # Render Methods
-    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
 
     def previewRender(self):
         image = BlankFrame(self.width, self.height)
@@ -371,15 +123,18 @@ class Component(QtCore.QObject, metaclass=ComponentMetaclass):
     def postFrameRender(self):
         pass
 
-    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
     # Properties
-    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
 
     def properties(self):
         """
-        Return a list of properties to signify if your component is
-        non-animated ('static'), returns sound ('audio'), or has
-        encountered an error in configuration ('error').
+        Return a list of properties with certain meanings:
+        `static`: non-animated
+        `audio`: has extra sound to add
+        `error`: bad configuration
+        `pcm`: request raw audio data
+        `composite`: request frame to draw on
         """
         return []
 
@@ -403,9 +158,9 @@ class Component(QtCore.QObject, metaclass=ComponentMetaclass):
         https://ffmpeg.org/ffmpeg-filters.html
         """
 
-    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
     # Idle Methods
-    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
 
     def widget(self, parent):
         """
@@ -510,9 +265,9 @@ class Component(QtCore.QObject, metaclass=ComponentMetaclass):
         self.commandHelp()
         quit(0)
 
-    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
     # "Private" Methods
-    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+    # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
     def _preUpdate(self):
         """Happens before subclass update()"""
         for attr in self._relativeWidgets:
@@ -826,153 +581,3 @@ class Component(QtCore.QObject, metaclass=ComponentMetaclass):
         maxRes = int(self.core.resolutions[0].split("x")[0])
         newMaximumValue = self.width * (self._relativeMaximums[attr] / maxRes)
         self._trackedWidgets[attr].setMaximum(int(newMaximumValue))
-
-
-class ComponentError(RuntimeError):
-    """Gives the MainWindow a traceback to display, and cancels the export."""
-
-    prevErrors = []
-    lastTime = time.time()
-
-    def __init__(self, caller, name, msg=None):
-        if msg is None and sys.exc_info()[0] is not None:
-            msg = str(sys.exc_info()[1])
-        else:
-            msg = "Unknown error."
-        log.error("ComponentError by %s's %s: %s" % (caller.name, name, msg))
-
-        # Don't create multiple windows for quickly repeated messages
-        if len(ComponentError.prevErrors) > 1:
-            ComponentError.prevErrors.pop()
-        ComponentError.prevErrors.insert(0, name)
-        curTime = time.time()
-        if (
-            name in ComponentError.prevErrors[1:]
-            and curTime - ComponentError.lastTime < 1.0
-        ):
-            return
-        ComponentError.lastTime = time.time()
-
-        from .toolkit import formatTraceback
-
-        if sys.exc_info()[0] is not None:
-            string = "%s component (#%s): %s encountered %s %s: %s" % (
-                caller.__class__.name,
-                str(caller.compPos),
-                name,
-                (
-                    "an"
-                    if any(
-                        [
-                            sys.exc_info()[0].__name__.startswith(vowel)
-                            for vowel in ("A", "I", "U", "O", "E")
-                        ]
-                    )
-                    else "a"
-                ),
-                sys.exc_info()[0].__name__,
-                str(sys.exc_info()[1]),
-            )
-            detail = formatTraceback(sys.exc_info()[2])
-        else:
-            string = name
-            detail = "Attributes:\n%s" % (
-                "\n".join([m for m in dir(caller) if not m.startswith("_")])
-            )
-
-        super().__init__(string)
-        caller.lockError(string)
-        caller._error.emit(string, detail)
-
-
-class ComponentUpdate(QUndoCommand):
-    """Command object for making a component action undoable"""
-
-    def __init__(self, parent, oldWidgetVals, modifiedVals):
-        super().__init__("change %s component #%s" % (parent.name, parent.compPos))
-        self.undone = False
-        self.res = (int(parent.width), int(parent.height))
-        self.parent = parent
-        self.oldWidgetVals = {
-            attr: (
-                copy(val)
-                if attr not in self.parent._relativeWidgets
-                else self.parent.floatValForAttr(attr, val, axis=self.res)
-            )
-            for attr, val in oldWidgetVals.items()
-            if attr in modifiedVals
-        }
-        self.modifiedVals = {
-            attr: (
-                val
-                if attr not in self.parent._relativeWidgets
-                else self.parent.floatValForAttr(attr, val, axis=self.res)
-            )
-            for attr, val in modifiedVals.items()
-        }
-
-        # Because relative widgets change themselves every update based on
-        # their previous value, we must store ALL their values in case of undo
-        self.relativeWidgetValsAfterUndo = {
-            attr: copy(getattr(self.parent, attr))
-            for attr in self.parent._relativeWidgets
-        }
-
-        # Determine if this update is mergeable
-        self.id_ = -1
-        if self.parent.mergeUndo:
-            if len(self.modifiedVals) == 1:
-                attr, val = self.modifiedVals.popitem()
-                self.id_ = sum([ord(letter) for letter in attr[-14:]])
-                self.modifiedVals[attr] = val
-                return
-            log.warning(
-                "%s component settings changed at once. (%s)",
-                len(self.modifiedVals),
-                repr(self.modifiedVals),
-            )
-
-    def id(self):
-        """If 2 consecutive updates have same id, Qt will call mergeWith()"""
-        return self.id_
-
-    def mergeWith(self, other):
-        self.modifiedVals.update(other.modifiedVals)
-        return True
-
-    def setWidgetValues(self, attrDict):
-        """
-        Mask the component's usual method to handle our
-        relative widgets in case the resolution has changed.
-        """
-        newAttrDict = {
-            attr: (
-                val
-                if attr not in self.parent._relativeWidgets
-                else self.parent.pixelValForAttr(attr, val)
-            )
-            for attr, val in attrDict.items()
-        }
-        self.parent.setWidgetValues(newAttrDict)
-
-    def redo(self):
-        if self.undone:
-            log.info("Redoing component update")
-        self.parent.oldAttrs = self.relativeWidgetValsAfterUndo
-        self.setWidgetValues(self.modifiedVals)
-        self.parent.update(auto=True)
-        self.parent.oldAttrs = None
-        if not self.undone:
-            self.relativeWidgetValsAfterRedo = {
-                attr: copy(getattr(self.parent, attr))
-                for attr in self.parent._relativeWidgets
-            }
-            self.parent._sendUpdateSignal()
-
-    def undo(self):
-        log.info("Undoing component update")
-        self.undone = True
-        self.parent.oldAttrs = self.relativeWidgetValsAfterRedo
-        self.setWidgetValues(self.oldWidgetVals)
-        self.parent.update(auto=True)
-        self.parent.oldAttrs = None
diff --git a/src/avp/libcomponent/exceptions.py b/src/avp/libcomponent/exceptions.py
new file mode 100644
index 0000000..5498414
--- /dev/null
+++ b/src/avp/libcomponent/exceptions.py
@@ -0,0 +1,63 @@
+import time
+import sys
+import logging
+
+from ..toolkit import formatTraceback
+
+
+log = logging.getLogger("AVP.ComponentHandler")
+
+
+class ComponentError(RuntimeError):
+    """Gives the MainWindow a traceback to display, and cancels the export."""
+
+    prevErrors = []
+    lastTime = time.time()
+
+    def __init__(self, caller, name, msg=None):
+        if msg is None and sys.exc_info()[0] is not None:
+            msg = str(sys.exc_info()[1])
+        else:
+            msg = "Unknown error."
+        log.error("ComponentError by %s's %s: %s" % (caller.name, name, msg))
+
+        # Don't create multiple windows for quickly repeated messages
+        if len(ComponentError.prevErrors) > 1:
+            ComponentError.prevErrors.pop()
+        ComponentError.prevErrors.insert(0, name)
+        curTime = time.time()
+        if (
+            name in ComponentError.prevErrors[1:]
+            and curTime - ComponentError.lastTime < 1.0
+        ):
+            return
+        ComponentError.lastTime = time.time()
+
+        if sys.exc_info()[0] is not None:
+            string = "%s component (#%s): %s encountered %s %s: %s" % (
+                caller.__class__.name,
+                str(caller.compPos),
+                name,
+                (
+                    "an"
+                    if any(
+                        [
+                            sys.exc_info()[0].__name__.startswith(vowel)
+                            for vowel in ("A", "I", "U", "O", "E")
+                        ]
+                    )
+                    else "a"
+                ),
+                sys.exc_info()[0].__name__,
+                str(sys.exc_info()[1]),
+            )
+            detail = formatTraceback(sys.exc_info()[2])
+        else:
+            string = name
+            detail = "Attributes:\n%s" % (
+                "\n".join([m for m in dir(caller) if not m.startswith("_")])
+            )
+
+        super().__init__(string)
+        caller.lockError(string)
+        caller._error.emit(string, detail)
diff --git a/src/avp/libcomponent/metaclass.py b/src/avp/libcomponent/metaclass.py
new file mode 100644
index 0000000..e8ad949
--- /dev/null
+++ b/src/avp/libcomponent/metaclass.py
@@ -0,0 +1,257 @@
+import os
+import logging
+from PyQt6 import QtCore
+
+from .exceptions import ComponentError
+from ..toolkit import connectWidget
+from ..toolkit.frame import BlankFrame
+
+log = logging.getLogger("AVP.ComponentHandler")
+
+
+class ComponentMetaclass(type(QtCore.QObject)):
+    """
+    Checks the validity of each Component class and mutates some attrs.
+    E.g., takes only major version from version string & decorates methods
+    """
+
+    def initializationWrapper(func):
+        def initializationWrapper(self, *args, **kwargs):
+            try:
+                return func(self, *args, **kwargs)
+            except Exception:
+                try:
+                    raise ComponentError(self, "initialization process")
+                except ComponentError:
+                    return
+
+        return initializationWrapper
+
+    def renderWrapper(func):
+        def renderWrapper(self, *args, **kwargs):
+            try:
+                log.verbose(
+                    "### %s #%s renders a preview frame ###",
+                    self.__class__.name,
+                    str(self.compPos),
+                )
+                return func(self, *args, **kwargs)
+            except Exception as e:
+                try:
+                    if e.__class__.__name__.startswith("Component"):
+                        raise
+                    else:
+                        raise ComponentError(self, "renderer")
+                except ComponentError:
+                    return BlankFrame()
+
+        return renderWrapper
+
+    def commandWrapper(func):
+        """Intercepts the command() method to check for global args"""
+
+        def commandWrapper(self, arg):
+            if arg.startswith("preset="):
+                _, preset = arg.split("=", 1)
+                path = os.path.join(self.core.getPresetDir(self), preset)
+                if not os.path.exists(path):
+                    print('Couldn\'t locate preset "%s"' % preset)
+                    quit(1)
+                else:
+                    print('Opening "%s" preset on layer %s' % (preset, self.compPos))
+                    self.core.openPreset(path, self.compPos, preset)
+                    # Don't call the component's command() method
+                    return
+            else:
+                return func(self, arg)
+
+        return commandWrapper
+
+    def propertiesWrapper(func):
+        """Intercepts the usual properties if the properties are locked."""
+
+        def propertiesWrapper(self):
+            if self._lockedProperties is not None:
+                return self._lockedProperties
+            else:
+                try:
+                    return func(self)
+                except Exception:
+                    try:
+                        raise ComponentError(self, "properties")
+                    except ComponentError:
+                        return []
+
+        return propertiesWrapper
+
+    def errorWrapper(func):
+        """Intercepts the usual error message if it is locked."""
+
+        def errorWrapper(self):
+            if self._lockedError is not None:
+                return self._lockedError
+            else:
+                return func(self)
+
+        return errorWrapper
+
+    def loadPresetWrapper(func):
+        """Wraps loadPreset to handle the self.openingPreset boolean"""
+
+        class openingPreset:
+            def __init__(self, comp):
+                self.comp = comp
+
+            def __enter__(self):
+                self.comp.openingPreset = True
+
+            def __exit__(self, *args):
+                self.comp.openingPreset = False
+
+        def presetWrapper(self, *args):
+            with openingPreset(self):
+                try:
+                    return func(self, *args)
+                except Exception:
+                    try:
+                        raise ComponentError(self, "preset loader")
+                    except ComponentError:
+                        return
+
+        return presetWrapper
+
+    def updateWrapper(func):
+        """
+        Calls _preUpdate before every subclass update().
+        Afterwards, for non-user updates, calls _autoUpdate().
+        For undoable updates triggered by the user, calls _userUpdate()
+        """
+
+        class wrap:
+            def __init__(self, comp, auto):
+                self.comp = comp
+                self.auto = auto
+
+            def __enter__(self):
+                self.comp._preUpdate()
+
+            def __exit__(self, *args):
+                if (
+                    self.auto
+                    or self.comp.openingPreset
+                    or not hasattr(self.comp.parent, "undoStack")
+                ):
+                    log.verbose("Automatic update")
+                    self.comp._autoUpdate()
+                else:
+                    log.verbose("User update")
+                    self.comp._userUpdate()
+
+        def updateWrapper(self, **kwargs):
+            auto = kwargs["auto"] if "auto" in kwargs else False
+            with wrap(self, auto):
+                try:
+                    return func(self)
+                except Exception:
+                    try:
+                        raise ComponentError(self, "update method")
+                    except ComponentError:
+                        return
+
+        return updateWrapper
+
+    def widgetWrapper(func):
+        """Connects all widgets to update method after the subclass's method"""
+
+        class wrap:
+            def __init__(self, comp):
+                self.comp = comp
+
+            def __enter__(self):
+                pass
+
+            def __exit__(self, *args):
+                for widgetList in self.comp._allWidgets.values():
+                    for widget in widgetList:
+                        log.verbose("Connecting %s", str(widget.__class__.__name__))
+                        connectWidget(widget, self.comp.update)
+
+        def widgetWrapper(self, *args, **kwargs):
+            auto = kwargs["auto"] if "auto" in kwargs else False
+            with wrap(self):
+                try:
+                    return func(self, *args, **kwargs)
+                except Exception:
+                    try:
+                        raise ComponentError(self, "widget creation")
+                    except ComponentError:
+                        return
+
+        return widgetWrapper
+
+    def __new__(cls, name, parents, attrs):
+        if "ui" not in attrs:
+            # Use module name as ui filename by default
+            attrs["ui"] = (
+                "%s.ui" % os.path.splitext(attrs["__module__"].split(".")[-1])[0]
+            )
+
+        decorate = (
+            "names",  # Class methods
+            "error",
+            "audio",
+            "properties",  # Properties
+            "preFrameRender",
+            "previewRender",
+            "loadPreset",
+            "command",
+            "update",
+            "widget",
+        )
+
+        # Auto-decorate methods
+        for key in decorate:
+            if key not in attrs:
+                continue
+            if key in ("names"):
+                attrs[key] = classmethod(attrs[key])
+            elif key in ("audio"):
+                attrs[key] = property(attrs[key])
+            elif key == "command":
+                attrs[key] = cls.commandWrapper(attrs[key])
+            elif key == "previewRender":
+                attrs[key] = cls.renderWrapper(attrs[key])
+            elif key == "preFrameRender":
+                attrs[key] = cls.initializationWrapper(attrs[key])
+            elif key == "properties":
+                attrs[key] = cls.propertiesWrapper(attrs[key])
+            elif key == "error":
+                attrs[key] = cls.errorWrapper(attrs[key])
+            elif key == "loadPreset":
+                attrs[key] = cls.loadPresetWrapper(attrs[key])
+            elif key == "update":
+                attrs[key] = cls.updateWrapper(attrs[key])
+            elif key == "widget" and parents[0] != QtCore.QObject:
+                attrs[key] = cls.widgetWrapper(attrs[key])
+
+        # Turn version string into a number
+        try:
+            if "version" not in attrs:
+                log.error(
+                    "No version attribute in %s. Defaulting to 1",
+                    attrs["name"],
+                )
+                attrs["version"] = 1
+            else:
+                attrs["version"] = int(attrs["version"].split(".")[0])
+        except ValueError:
+            log.critical(
+                "%s component has an invalid version string:\n%s",
+                attrs["name"],
+                str(attrs["version"]),
+            )
+        except KeyError:
+            log.critical("%s component has no version string.", attrs["name"])
+        else:
+            return super().__new__(cls, name, parents, attrs)
+        quit(1)
diff --git a/src/avp/toolkit/ffmpeg.py b/src/avp/toolkit/ffmpeg.py
index 5aedff3..93aa725 100644
--- a/src/avp/toolkit/ffmpeg.py
+++ b/src/avp/toolkit/ffmpeg.py
@@ -11,7 +11,7 @@ import signal
 from queue import PriorityQueue
 import logging
 
-from .. import core
+from ..core import Core
 from .common import checkOutput, pipeWrapper
 
 
@@ -19,7 +19,7 @@ log = logging.getLogger("AVP.Toolkit.Ffmpeg")
 
 
 class FfmpegVideo:
-    """Opens a pipe to ffmpeg and stores a buffer of raw video frames."""
+    """Opens an input pipe to ffmpeg and stores a buffer of raw video frames."""
 
     # error from the thread used to fill the buffer
     threadError = None
@@ -53,7 +53,7 @@ class FfmpegVideo:
             kwargs["filter_"] = None
 
         self.command = [
-            core.Core.FFMPEG_BIN,
+            Core.FFMPEG_BIN,
             "-thread_queue_size",
             "512",
             "-r",
@@ -98,11 +98,11 @@ class FfmpegVideo:
             self.frameBuffer.task_done()
 
     def fillBuffer(self):
-        from ..component import ComponentError
+        from ..libcomponent import ComponentError
 
-        if core.Core.logEnabled:
+        if Core.logEnabled:
             logFilename = os.path.join(
-                core.Core.logDir, "render_%s.log" % str(self.component.compPos)
+                Core.logDir, "render_%s.log" % str(self.component.compPos)
             )
             log.debug("Creating ffmpeg process (log at %s)", logFilename)
             with open(logFilename, "w") as logf:
@@ -176,7 +176,7 @@ def findFfmpeg():
 
     if getattr(sys, "frozen", False):
         # The application is frozen
-        bin = os.path.join(core.Core.wd, bin)
+        bin = os.path.join(Core.wd, bin)
 
     with open(os.devnull, "w") as f:
         try:
@@ -187,7 +187,9 @@ def findFfmpeg():
     return bin
 
 
-def createFfmpegCommand(inputFile, outputFile, components, duration=-1):
+def createFfmpegCommand(
+    inputFile, outputFile, components, duration=-1, logLevel="info"
+):
     """
     Constructs the major ffmpeg command used to export the video
     """
@@ -195,7 +197,6 @@ def createFfmpegCommand(inputFile, outputFile, components, duration=-1):
         duration = getAudioDuration(inputFile)
     safeDuration = "{0:.3f}".format(duration - 0.05)  # used by filters
     duration = "{0:.3f}".format(duration + 0.1)  # used by input sources
-    Core = core.Core
 
     # Test if user has libfdk_aac
     encoders = checkOutput("%s -encoders -hide_banner" % Core.FFMPEG_BIN, shell=True)
@@ -243,6 +244,8 @@ def createFfmpegCommand(inputFile, outputFile, components, duration=-1):
 
     ffmpegCommand = [
         Core.FFMPEG_BIN,
+        "-loglevel",
+        logLevel,
         "-thread_queue_size",
         "512",
         "-y",  # overwrite the output file if it already exists.
@@ -415,7 +418,7 @@ def createAudioFilterCommand(extraAudio, duration):
 def testAudioStream(filename):
     """Test if an audio stream definitely exists"""
     audioTestCommand = [
-        core.Core.FFMPEG_BIN,
+        Core.FFMPEG_BIN,
         "-i",
         filename,
         "-vn",
@@ -433,7 +436,7 @@ def testAudioStream(filename):
 
 def getAudioDuration(filename):
     """Try to get duration of audio file as float, or False if not possible"""
-    command = [core.Core.FFMPEG_BIN, "-i", filename]
+    command = [Core.FFMPEG_BIN, "-i", filename]
 
     try:
         fileInfo = checkOutput(command, stderr=subprocess.STDOUT)
@@ -473,7 +476,7 @@ def readAudioFile(filename, videoWorker):
         return
 
     command = [
-        core.Core.FFMPEG_BIN,
+        Core.FFMPEG_BIN,
         "-i",
         filename,
         "-f",
@@ -498,7 +501,7 @@ def readAudioFile(filename, videoWorker):
     progress = 0
     lastPercent = None
     while True:
-        if core.Core.canceled:
+        if Core.canceled:
             return
         # read 2 seconds of audio
         progress += 4
@@ -543,3 +546,18 @@ def exampleSound(style="white", extra="apulsator=offset_l=0.35:offset_r=0.67"):
         src = "0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
 
     return "aevalsrc='%s', %s%s" % (src, extra, ", " if extra else "")
+
+
+def checkFfmpegVersion():
+    try:
+        with open(os.devnull, "w") as f:
+            ffmpegVers = checkOutput([Core.FFMPEG_BIN, "-version"], stderr=f)
+        ffmpegVers = str(ffmpegVers).split()[2].split(".", 1)[0]
+        if ffmpegVers.startswith("n"):
+            ffmpegVers = ffmpegVers[1:]
+        versionNum = int(ffmpegVers)
+        goodVersion = versionNum > 3
+    except Exception:
+        versionNum = -1
+        goodVersion = False
+    return goodVersion, versionNum
diff --git a/src/avp/toolkit/visualizer.py b/src/avp/toolkit/visualizer.py
index c55a3f3..6477559 100644
--- a/src/avp/toolkit/visualizer.py
+++ b/src/avp/toolkit/visualizer.py
@@ -14,6 +14,7 @@ def createSpectrumArray(
     progressBarUpdate,
     progressBarSetText,
 ):
+    lastProgress = 0
     lastSpectrum = None
     spectrumArray = {}
     for i in range(0, len(completeAudioArray), sampleSize):
@@ -33,9 +34,12 @@ def createSpectrumArray(
         progress = int(100 * (i / len(completeAudioArray)))
         if progress >= 100:
             progress = 100
+        if progress == lastProgress:
+            continue
         progressText = f"Analyzing audio: {str(progress)}%"
         progressBarSetText.emit(progressText)
         progressBarUpdate.emit(int(progress))
+        lastProgress = progress
     return spectrumArray
 
 
diff --git a/src/avp/video_thread.py b/src/avp/video_thread.py
index 967d2fe..ecd8c4c 100644
--- a/src/avp/video_thread.py
+++ b/src/avp/video_thread.py
@@ -12,16 +12,16 @@ from PyQt6 import QtCore, QtGui
 from PyQt6.QtCore import pyqtSignal, pyqtSlot
 from PIL import Image
 from PIL.ImageQt import ImageQt
+
 import numpy
 import subprocess as sp
 import sys
 import os
-import time
 import signal
 import logging
 
-from .component import ComponentError
-from .toolkit.frame import Checkerboard
+from .libcomponent import ComponentError
+from .toolkit import formatTraceback
 from .toolkit.ffmpeg import (
     openPipe,
     readAudioFile,
@@ -61,7 +61,11 @@ class Worker(QtCore.QObject):
     def createFfmpegCommand(self, duration):
         try:
             ffmpegCommand = createFfmpegCommand(
-                self.inputFile, self.outputFile, self.components, duration
+                self.inputFile,
+                self.outputFile,
+                self.components,
+                duration,
+                "info" if log.getEffectiveLevel() < logging.WARNING else "error",
             )
         except sp.CalledProcessError as e:
             # FIXME video_thread should own this error signal, not components
@@ -111,6 +115,7 @@ class Worker(QtCore.QObject):
         Also prerenders "static" components like text and merges them if possible
         """
         self.staticComponents = {}
+        self.compositeComponents = set()
 
         # Call preFrameRender on each component
         canceledByComponent = False
@@ -160,6 +165,8 @@ class Worker(QtCore.QObject):
             if "static" in compProps:
                 log.info("Saving static frame from #%s %s", compNo, comp)
                 self.staticComponents[compNo] = comp.frameRender(0).copy()
+            elif compNo > 0 and "composite" in compProps:
+                self.compositeComponents.add(compNo)
 
         # Check if any errors occured
         log.debug("Checking if a component wishes to cancel the export...")
@@ -208,9 +215,11 @@ class Worker(QtCore.QObject):
             self.closePipe()
             self.cancelExport()
             self.error = True
-            msg = "A call to renderFrame in the video thread failed critically."
-            log.critical(msg)
-            comp._error.emit(msg, str(e))
+            msg = f"{comp.name} renderFrame({int(audioI / self.sampleSize)}) raised an exception."
+            tb = formatTraceback()
+            details = f"{e.__class__.__name__}: {str(e)}\n\n{tb}"
+            log.critical(f"{msg}\n{details}")
+            comp._error.emit(msg, details)
 
         bgI = int(audioI / self.sampleSize)
         frame = None
@@ -230,6 +239,9 @@ class Worker(QtCore.QObject):
                             frame, self.staticComponents[layerNo]
                         )
 
+                elif layerNo in self.compositeComponents:
+                    # component that uses previous frame to draw
+                    frame = Image.alpha_composite(frame, comp.frameRender(bgI, frame))
                 else:
                     # animated component
                     if frame is None:  # bottom-most layer
@@ -309,9 +321,9 @@ class Worker(QtCore.QObject):
             log.critical("Out_Pipe to FFmpeg couldn't be created!", exc_info=True)
             raise
 
-        # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+        # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
         # START CREATING THE VIDEO
-        # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+        # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
         progressBarValue = 0
         self.progressBarUpdate.emit(progressBarValue)
         # Begin piping into ffmpeg!
@@ -335,16 +347,13 @@ class Worker(QtCore.QObject):
             completion = (audioI / self.audioArrayLen) * 100
             if progressBarValue + 1 <= completion:
                 progressBarValue = numpy.floor(completion).astype(int)
+                msg = "Exporting video: %s%%" % str(int(progressBarValue))
                 self.progressBarUpdate.emit(progressBarValue)
-                self.progressBarSetText.emit(
-                    "Exporting video: %s%%" % str(int(progressBarValue))
-                )
+                self.progressBarSetText.emit(msg)
 
-        # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
+        # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
         # Finished creating the video!
-        # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~==~=~=~=~=~=~=~=~=~=~=~=~=~=~
-
-        numpy.seterr(all="print")
+        # =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
 
         self.closePipe()
 
@@ -363,7 +372,7 @@ class Worker(QtCore.QObject):
             if self.error:
                 self.failExport()
             else:
-                print("Export Complete")
+                print("\nExport Complete")
                 self.progressBarUpdate.emit(100)
                 self.progressBarSetText.emit("Export Complete")